Objective: To explore the protective effects of Huqi extractum, a compound Chinese herbal medicine, on salivary glands against radiation in Wistar rats.
Methods: One hundred Wistar rats were randomly divided into sham-exposure group, untreated group, and low-, medium- and high-dose Huqi groups. Local irradiation of ⁶⁰Co gamma-rays with a single dose of 15 Gy was applied to the salivary glands of the Wistar rats except the sham-exposure group. After 3- and 40-day treatment, saliva was collected. Colorimetric method, iodine-amylase colorimetric method and enzyme-linked immunosorbent assay were used to detect concentrations of sodium (Na⁺), potassium (K⁺) and secretory immunoglobulin A (sIgA) and activity of salivary amylase. Pathological changes of salivary gland tissues were observed by hematoxylin-eosin straining.
Results: After 3-day administration, radiation-induced salivary gland injuries were obvious and prevalent in irradiated rats. Comparing with the sham-exposure group, saliva concentration of sIgA and body weight were reduced in other irradiated groups, except those in the high-dose Huqi group, while salivary amylase level was increased. At 3-day phase, pathologic changes of the salivary glands were featured as swelling acinus plasm and vacuolation. At 40-day phase, atrophy of gland cells was dominant. After 40-day administration, there were no significant differences between the high-dose Huqi group and sham-exposure group in sIgA and amylase levels and body weight, and according to the histological examination, no significant difference was revealed under the optical microscope.
Conclusion: Chinese herbal medicine is helpful for the recovery of the salivary glands from the radiation injury, morphologically and functionally in rats.

Key words: supplementing qi and nourishing yin, Chinese herbal medicine, radiation protection, salivary gland, rats